ATP
Uses of Energy:
- Synthesis: for making large molecules such as proteins.
- Transport: for example pumping molecules across cell membranes.
- Movement: to make protein fibres in muscle cells contract.
- Adenosine triphosphate is able to supply energy to cells in a manageable way.
- It is a nucleotide comprised of three phosphate groups, a pentose ribose sugar and an adenine nitrogenous base.
Energy Release:
- When the bonds between the last two phosphate groups are broken, 30.6kJ/Mol of energy is released. This is usually more energy than required.
- The breaking of the phosphate groups is a hydrolysis reaction.
- Because of the instability of phosphate bonds in ATP, it is not a good long term energy store. Fats and carbohydrates are better at this.
- Instead rapid phosphorylation occurs when energy is required. This means we need a relatively small amount of ATP.
- Phosphorylation is a condensation reaction where an inorganic phosphate group is reattached to an ADP molecule.
- Small - moves easily in, out and around cells.
- Soluble - most active processes happen in aqueous environments.
- Intermediate amounts of energy released: enough for cellular reactions, but not so much that it is all wasted as heat.
- Easily Regenerated - renewable energy source.